Hydraulic Oil Research Articles

Electronic Control System for Steer by Wire

Automobile industry’s focus is on efficiency, safety and performance has resulted in the rapid introduction of electronics in vehicle safety systems and engine management. Mechanical and Hydraulic systems are now gradually being replaced by electronic controllers to achieve the objectives of optimizing power consumption, improving driver convenience, and maximizing driver safety resulting in an overall improved performance and experience. Vehicle steering systems have transitioned from mechanical to hydraulic power to an electric power assisted steering system and now to the state of the art, Steer by Wire (SbW) system. Traditional mechanical systems included a steering wheel, column, gear, rack and pinion and did not support any power steering. The next generation hydraulic systems were more stable, safer and required comparatively lesser effort. Electric or DC motors drove the Electric Power System addressing the drawbacks of the hydraulic systems especially those related to environment and acoustics with the added advantage of a compact structure and power-on-demand engine performance. By-wire steering technologies was originally introduced in the Concord aircraft in 1970s. The SbW is a steering system with no steering column. The mechanical interface between the steering wheel and the wheels is replaced with by-wire electrical connection/electronic actuators. SbW system has significant advantages in terms of driving safety due to the availability of the steering command in electronic form and the removal of the steering shaft, cruising comfort with driving manoeuvring due to no space constraint and favourable to the environment with the non-usage of hydraulic oils.

Numerical investigation on performance improvement of latent heat exchanger with sextant helical baffles

• Numerical investigation on a novel latent heat exchanger with sextant helical baffles was implemented. • Helix angle exhibits an opposite effect on the thermal performance and comprehensive performance of shell side. • The thermal conductivity and pr number of the HTF are important factors affecting the shell-side heat transfer feature. • Internal-external fin structure shows a large impact on the melting process of PCM. • Nano-additives have a remarkable influence on the thermal conductivity and latent heat of Nano-PCMs. Latent heat thermal energy storage is a promising technology, which is becoming more and more widespread in industrial fields. A novel latent heat exchanger with sextant helical baffles is thus investigated numerically in this paper. The different helix angles (10°, 20°, 30°, 40°) of sextant helical baffle are employed to explore the shell-side thermal and comprehensive performances in latent heat exchanger. The geometric parameters of internal-external fins, including the height, thickness and shape, are studied to improve the melting rate of phase change material (PCM). Water, fuel oil JP-4, ethylene glycol and hydraulic oil are chosen as heat transfer fluids (HTFs). Nano-PCMs with various volume concentrations of TiO 2 (2%, 4% and 6%) are used to study the discharging characteristic of latent heat exchanger. The results indicate that shell-side heat transfer and integrated behaviors need to be considered comprehensively for the choice of helix angle. The longitudinal-shaped fin with 7.5 mm height and 1 mm thickness is studied as the optimal scheme. Smaller Pr number and larger thermal conductivity are applied to HTF to further enhance the heat transfer between HTF and PCM. Furthermore, the selection of Nano-PCM needs to comprehensively consider the requirements of thermal conductivity and phase change latent heat in practical application.

Sludge Formation Analysis in Hydraulic Oil of Load Haul Dumper 811MK V Machine Running at Elevated Temperatures for Bioenergy Applications

Hydraulic oil degrades expediently during operating at elevated temperatures, and due to oil degradation, malfunction of all hydraulic components starts that hampers the hydraulic functioning of the machine. An inefficient component of the hydraulic system converts useful energy into heat. Overheating starts when the rate of heat energy escaping from the system overcomes the rate of heat dissipation. Viscosity, total acidic number (TAN), rheology, and FTIR analyses were carried out on the oil samples collected chronically, and the reasons for degradation and sludge formation were evaluated; the results showed that thermal cracking resistance capacity of the oil was low due to the imbalance percentage of additives in the base oil. Sludge impaired the system efficiency and prejudicially creates repercussions on power consumption. Sludge can be recycled for biofuel and to avoid imbalance in the ecosystem. The test result is plotted in a 3D view graph using the MATLAB R 2019 software for a better explanation. Variation in the behaviour of the hydraulic fluid with respect to time, temperature, shear stress, and shear rate was studied, and the result is validated with correlation and regression analyses.

Osmotic engine converting energy from salinity difference to a hydraulic accumulator by utilizing polyelectrolyte hydrogels

Efficient harvesting of the mixing energy from the salinity gradient between sea and river water remains a challenge. Recently, utilization of the swelling/shrinking properties of hydrogels has been explored as a new means for extracting this energy. However, former investigations are mainly limited to examining the performance of the hydrogels when lifting applied weights, and calculating the energy that could potentially be extracted. In this study, we demonstrate a novel osmotic engine with a mechanical energy transmission prototype, which can convert and store the green mixing energy in a form that can be utilized to perform mechanical work. The osmotic engine includes a cylinder containing the hydrogel, an oil-hydraulic cylinder and a hydraulic accumulator. The lifting energy from the hydrogel is transferred to the oil-hydraulic cylinder through a lever, which acts as a pump and accumulate the hydraulic oil under high pressure in the hydraulic accumulator. The system was tested with a hydrogel of poly(acrylic acid) semi-interpenetrated with poly(4-styrenessulfonic acid-co-maleic acid) sodium. This hydrogel produced up to 36 J per shrinking/swelling cycle, and exhibited an efficiency of 0.53% at optimum conditions.

Performance Features of Tooth Gearing in Gear Hydraulic Machines

Abstract The paper presented determines that the rotation velocities of gears and radii connecting the axes of rotation of the gears with the point of their teeth gearing are not equal with each other. It is explained by the relative slip of involute gear profiles during their rolling. This phenomenon will become a prerequisite for further development of creation of mathematical models in the context of theory of gear hydraulic machines. The models can explain a number of specific phenomena in the operation of gear hydraulic machines, such as pressure and input pulsations, dynamics of hydraulic oil in the cut-off plane, combined torque pulsations in gear hydraulic motors and others.

Research on improved hydrostatic guideway base thermal characteristics by flattening temperature distribution

This paper proposed a new guideway base structure of hydrostatic guideways to flatten its spatial temperature variation characteristics. Four oil storage holes penetrating through the base are used to collect the hydraulic oil, which is heated by power losses after oil flows through the bearing clearances. When the heated oil flows into the four oil storage holes, the whole base is warmed and temperature distribution non-uniformity is avoided. In order to verify the effectiveness of the new structure, a physical model of the guideway base simplified from actual base was developed. A thermal model of a guideway base was developed using the finite element method (FEM). The temperature distribution of guideway bases was calculated, taking into account the temperature-dependent heat transfer coefficients of interfaces and thermal contact conductances. Analysis of temperature differences, thermal equilibrium time, and temperature uniformity of bases demonstrates the effectiveness of the new base design on its thermal characteristics and improves structural parameters. The experimental results verify the accuracy of the thermal model hydrostatic guideway bases.

Wear of AlCrN and CrAlSiN Coatings Applied to Nonstandard Involute Gears

Wear of nonstandard involute gears with two types of coatings, AlCrN and CrAlSiN, was studied. The coatings were applied by cathodic arc deposition. The gears were tested using a Niemann tester at a graduated load up to the 12th load stage and were compared to noncoated gears. Both Biogear S150 gear oil and PP90 universal hydraulic oil were applied during these tests. The thickness of deposited coatings and wear of gear teeth were studied by SEM and their chemical compositions were determined by EDS analysis. Maximal contact pressure of 1350 MPa was calculated in the region of the tooth flank at the 12th load stage. Maximal frictional stress was also calculated on the tooth flank. The resistance against wear of gears was evaluated based on the critical weight loss and mainly based on the critical surface roughness of gears. The critical roughness was exceeded at the 10th load stage for noncoated gears. For the gears with AlCrN and CrAlSiN coatings, the critical roughness was exceeded at the 11th load stage. Wear of AlCrN and CrAlSiN coatings was nonuniform along the height of tooth. Wear on the tooth flank was characterized by fragmentation of thin coatings and subsequent detaching of fragments from the steel substrate. The steel substrate was worn by microcutting, which caused the highest roughness on the tooth surface. On the tooth pitch, surface protrusions of coatings were smoothed, and coatings cracked and locally detached subsequently. On the tooth face, surface protrusions were also smoothed but coatings remained compact without crack initiations. Both experimental oils, Biogear S150 and PP90, proved to be suitable during Niemann tests as their temperatures did not exceed the limit value of 80 °C.

WITHDRAWN: Thermo mechanical properties of teflon composites with filled hydraulic oil

Mechanical components utilized in machinery, like nylon slider and simple machine, ought to have certain mechanical properties and smart tribological properties, so equipment’ stability and smoothness can be assured. A kind of megahertz nylon (monomer solid nylon) composites stuffed with hydraulic oil was studied during this paper. The addition of hydraulic oil-modified nylon’s mechanical properties and tribological properties significantly, and improved the material’s toughness and coefficient of friction. The composites have glorious strength, toughness, and relatively low constant of friction when the content of the hydraulic oil is 4 wt%.

Perawatan dan Perbaikan Sistem Hidrolik pada Dumping Dump Truck Mitsubishi Fuso 190Ps

Sistem hidrolik pada dump truck yang terdiri dari beberapa komponen memerlukan tindakan perawatan terencana, agar sistem hidrolik dapat berfungsi secara optimal. Tujuan penulisan adalah untuk dapat melakukan analisa kerusakan dan dapat melakukan tindakan perbaikan dengan tepat dan benar. Metode penganalisaan dalam analisa perawatan dan perbaikan sistem hidrolik ini ialah dengan menggunakan beberapa pertanyaan, yaitu apa, kenapa, dimana, dan bagaimana. Komponen utama sistem hidrolik dump truck yang memerlukan perawatan adalah seperti tangki hidrolik, pompa, katup, aktuator, filtrasi dan slang hidrolik, adapun penyebab utama kerusakan dari komponen sistem hidrolik tersebut adalah karena kebersihan oli hidrolik yang buruk, kontaminasi dalam sistem, dan kelebihan beban(over load). Untuk mengatasi kerusakan yang terjadi adalah dengan jalan menerapkan manajemen perawatan dan perbaikan yang benar, terencana dan sesuai SOP.

Modeling and Predictive Analysis of Small Internal Leakage of Hydraulic Cylinder Based on Neural Network

The internal leakage of a hydraulic cylinder is an inevitable hydraulic system failure that seriously affects the working efficiency of the hydraulic system. Therefore, it is very important to accurately identify and predict leakage data in the hydraulic cylinder. In this paper, a model is proposed to simulate a small internal leakage of hydraulic cylinders, to convert the amount of leakage of hydraulic oil into strain signals through high-precision strain gauges and to train the collected strain signals using various neural networks to form a computational model and obtain prediction results from the model. The neural networks applied in this paper are convolutional neural networks, BP neural networks, T-S neural networks and Elman neural networks. The predicted results of the neural network are compared with the actual leakage amount. The results show that the prediction accuracy of the above four kinds of neural networks are all above 90%, of which the convolutional neural network is the most accurate. This research provides scientific and technical support for measuring and predicting small leaks.

A pore–scale investigation of surface roughness on the evolution of natural fractures during acid dissolution using DBS method

Natural fractures are the essential pathways by which water, hydraulic fracturing fluids, oil and gas, reactants, and contaminants can travel in the porous media. To fully understand subsurface processes relevant to the fluid transport in natural fractures, the Darcy–Brinkmann–Stokes (DBS) pore–scale method was employed to investigate the effects of fracture surface roughness on the reactive transport and dissolution mechanisms of porous media with natural fractures. The advection–diffusion equation described the transport of reactants, and the incorporated mass balance equation dynamically tracked the fracture evolution during acid dissolution. The model has been developed based on the OpenFOAM platform, a CFD open–source code. The partial differential equations were discretized by the Finite Volume Method (FVM) on the structured grids. We studied the dissolution mechanisms, effective surface area, and normalized porosity–permeability relationship on different surface roughness. An Indiana limestone sample with different calcite content was investigated to elucidate the impacts of unreacted minerals on acidizing process. We categorized the solid dissolution of fractures into three dissolution patterns regarding the second Damkohler number and the Peclet number—face dissolution, front dissolution, and edge dissolution—, where the front dissolution pattern and the face dissolution pattern had the shorter time to consume up the rock in the fractured system. The quantified pore–scale parameters obtained from this study are expected to improve the accuracy of Darcy–scale models. The microscopic insights from the present study can guide effective operating parameters and enhance hydrocarbon production by optimizing the acidization process. • Pore–scale reactive transport and dissolution model in fractured porous media by DBS method. • Three dissolution and transport patterns in fractures were investigated. • The fracture evolution, dissolution rate, porosity–permeability relationship, effective surface area were elucidated. • μCT scan image model with different mineralogical content were analyzed.

Design of a Compact Embedded Hydraulic Power Unit for Bipedal Robots

This letter proposes a design method of a compact embedded hydraulic power unit (HPU) for a bipedal robot and a controller to regulate the supply pressure. The HPU consists of an integrated pump-motor unit. The unit is immersed in hydraulic oil for efficient space utilization and heat dissipation from the motor. This HPU design is analyzed to establish a relationship between the thermal variables and the motor design parameters such as gap radius and wire radius via its thermal and electrical modeling. Through this analysis, the design parameters of suitable pump-driving motor are chosen. This letter also proposes a control method for the HPU to regulate the supply pressure while minimizing the energy loss caused by the bypass through a pressure-regulating valve. The HPU is mounted on top of the bipedal robot platform, LIGHT, with twelve degrees of freedom actuated by the proposed HPU. Finally, the durability of the designed HPU is demonstrated through a long-term driving test at a high pressure. Furthermore, air-walking and squat motion experiments are conducted with the bipedal robot to demonstrate the capabilities of the HPU and its controller.

Investigation of potential damage to bridge infrastructure from induced earthquakes

This paper evaluates the fragility of bridges in areas exposed to induced seismic hazards, including human-caused earthquakes commonly associated with the petroleum industry and wastewater disposal. Recently, the rate of such ground motions has significantly increased, especially in areas with high levels of hydraulic fracturing oil extraction in the Central U.S. Induced earthquakes are generally small-to-moderate in magnitude; however, they typically happen in places with historically negligible seismicity, where the structures are designed considering no-to-low seismic demands. Therefore, the increased seismic activities in the region raise concerns about the safety of the infrastructure in that area. This study investigates the fragility of bridge portfolios subjected to induced earthquakes considering major sources of uncertainty in ground motions, bridge geometry, and material properties. Fragility curves are developed with respect to different intensity measures such as peak ground acceleration and velocity, as well as spectral accelerations. In addition, developed fragility curves are compared with those associated with other seismic hazards to evaluate the influence of ground motion characteristics on bridge fragility. The comparison includes similar magnitude natural earthquakes in the Western U.S., New Madrid seismic hazards (i.e., the historical seismic hazard of interest in the Central U.S.), and fragility estimates from HAZUS.

Modeling and Experimental Verification of a Semi-rotary Fluid Damper Based on an Improved Kelvin Model

The semi-rotary fluid damper is a shock-absorbing device that is widely used for the protections of various mechanical structures. In this research, a new small semi-rotary fluid damper for vibration reduction of helicopter control system is introduced. The damping medium used in the damper is hydraulic oil with a high shear thinning rate, which has a high degree of nonlinear hysteresis and viscoelastic properties. The accuracy of the mechanical model of the damper is of great significance to the design of control strategies for effective vibration reduction. Based on the adaptive genetic algorithm, the parameter identification of the semi-rotary fluid damper is studied with the objective function of minimizing the square of the difference between the analytical force and the experimental force. The Kelvin and generalized Kelvin with friction models lack parameters to properly describe the frequency and amplitude dependence. Therefore, an improved Kelvin model which is based on generalized Kelvin is proposed to capture the nonlinear dynamic characteristics of the damper. Through error analysis, it is concluded that the improved Kelvin model can more accurately describe the nonlinear damping characteristics of the semi-rotary fluid damper subjected to different amplitudes and frequencies.

Human-induced or natural hazard? Factors influencing perceptions of actions to be taken in response to induced seismicity

A relatively new term for categorizing hazards is that of “techna” hazards, or seemingly natural phenomena induced by human technology or activity. The human origin of these hazards means that mitigation aimed at addressing the underlying cause of the hazard is a possibility, which is often not considered possible with traditional natural hazards. Currently, however, there is a dearth of literature regarding how perceptions of the underlying cause of the hazard influences beliefs regarding disaster risk reduction strategies for the hazard. Thus, this work examines the factors that predict beliefs regarding whether a techna hazard can be stopped or reduced, the best actions that should be taken to reduce or stop the hazard event, and whether current regulation efforts aimed at stopping or controlling the activities causing the hazard are enough. We specifically examine the case of fluid injection induced seismicity in Oklahoma and Colorado in the United States. We find that, contrary to our expectations from prior literature, exposure to the hazard is not a strong predictive factor of these beliefs. Perceptions of the underlying activity associated with the hazard, in this case hydraulic fracturing and oil and gas development, is significant, in that those with more positive views of the industry activity are more likely to believe the earthquakes cannot be stopped and favor less intense regulative efforts to address the hazard.

Assessment of the influence of the working fluid production on the output parameters of the transmission hydraulic motor of the front loader

Problem. During the operation of the volumetric hydraulic drive of the front loader, as the surfaces of the movable interfaces of the hydraulic drive elements wear out, the gaps increase, and as a result, the leaks of the working fluid (WF) increase, and, therefore, the performance of the machine as a whole decreases. The resource of the hydraulic drive units is largely determined by the physicochemical properties of the WF, and in particular, the ability of the WF to reduce the specific load in the contact of the surfaces of the movable joints. During the operation of the transmission hydraulic drive, the aging of the fluid occurs. As a result, its operational properties deteriorate, including a decrease in the bearing capacity of the WF lubricant film. This leads to an increase in the wear of the interface surfaces of the volumetric hydraulic drive of the transmission (VHDT) and a decrease in the productivity of the machine. Goal. Experimental studies of the influence of the working fluid production on the rate of change of the volumetric efficiency of the hydraulic motor of the volumetric hydraulic drive of the front loader transmission have been carried out. Methodology. The tests of the MP-90 hydraulic motor were carried out at the stand. The object of the study was the hydraulic motor of the MP-90 frontal loader. Hydraulic oil MANITOU HUILE HYDRAULIQUE ISO HV46 with different operating time was used as the WF. Samples were taken from the transmission drive system of the PMTS-1200 front loader. The experimental ones were carried out under the following conditions: WF temperature, t = 323 K; rotational speed of the pump drive shaft, n = 25 s ; the operating time of the WF varied within the range of T = 0–720 motor-hours with a step of 200 motor-hours; the purity of RZ is not less than 10 class according to GOST 17216-2001; the test time was taken equal to 40 hours; pressure in the discharge line 26.5 MPa, vibration amplitude 6 MPa, vibration frequency 0.2 s. Results. It is shown that an increase in the operating time of the WF during the operation of the machine determines, other things being equal, an increase in the rate of change in the volumetric efficiency of the VHDT hydraulic motor. Originality. To prevent increased wear of the moving surfaces of the VHDT interfaces during the operation of the front-end loader, it is necessary to use WF the bearing capacity of the lubricating film which is higher than the maximum permissible value. Practical value. The use of the results of the study will increase the VHDT of the hydraulic drive elements of the front loader and reduce the rate of decrease in its productivity during its operation.

Research on test method and correlation of low temperature performance of hydraulic oil

At present, the low temperature test methods of hydraulic oil are characterized by low temperature kinematic viscosity, low temperature dynamic viscosity, low temperature pumping viscosity, low temperature brinell viscosity and pour point. In order to meet the different requirements of low temperature performance indexes of hydraulic oil products at home and abroad, the testing principles of various testing methods are introduced and analyzed, the flow performance of different testing methods under different working conditions is presented and the correlation between the methods is analyzed briefly.

Structured media based on magnetic colloids as a promising material for magnetically controllable optical elements

The magneto-optic effects in magnetic emulsions with low interfacial tension based on aviation hydraulic oil and in magnetic colloids with an extensive system of nanoparticle aggregates is investigated. The effect of changing the transparency in a longitudinal magnetic field is detected, the magnitude of which can be controlled by changing the strength and orientation of the magnetic field. In a transverse field, the effect of anisotropic diffractive scattering of light by irregular and regular systems of microdroplets elongated along the field is demonstrated. Diffraction patterns are obtained that can be configured by adjusting the ratio of components of a rotating magnetic field. It is concluded that magnetic emulsions and magnetic colloids with concentrated nanoparticle aggregates are promising as materials for magnetically controllable optical elements.

Numerical Investigation of Flow Characteristics in a Viscous Damping System with Symmetrical Hydraulic Cylinders

Hydraulic dampers are widely applied due to their characteristics of absorbing huge impact energy, stable and reliable working performance, and easy on-demand design. The hydraulic cylinder is an important part of the hydraulic damping system and the flow conditions inside the cylinder significantly affect its performance. However, only a few researches related to the flow field inside the hydraulic cylinder have been reported. In this study, a novel viscous damping system with opposing symmetrical hydraulic cylinders that can guarantee the smoothness of vibration absorption in a single degree of freedom is proposed. The advantage of this design is that the damping characteristic can be regulated using the external flow valve provided in the external hydraulic loop. The hydraulic damping system is simulated using the commercial software ANSYS Fluent software environment, different strokes and frequencies are applied to observe the internal flow characteristics. As can be seen from the results of numerical investigation, when the piston on one side moves, the piston on the other side also moves, and the pressure change in the cylinder is caused by the collective effect of the cavity volume change and the flow change of the hydraulic oil. In addition, by comparing the streamline and velocity distribution in the cavity under different strokes and frequencies, the relationship between vortex and velocity and compression distance is summarized. These results provide valuable information to facilitate the design of viscous damping system with symmetrical hydraulic cylinders.

Study on polyvinyl chloride nanofibers ability for oil spill elimination

Oil spill is a serious environmental pollution problem that affects the environment and human health. The immediate and efficient removal of oil spill has become an urgent problem. In recent decades, electrospinning technology has become an effective method for fabrication of nanofibers. Electrospun nanofibers have many applications in different fields, such as environment, healthcare, electrical field, and electronics. The present paper has studied the capacity of polyvinyl chloride nanofibers, which have been successfully obtained by electrospinning method for removal of oil from water. The morphology and hydrophobicity of nanofibers were studied. The sorption capacity of nanofibers has been investigated for various oils such as motor oil, hydraulic oil, and crude oil. The rate of oil sorption versus time, the effect of oil concentration, and temperature on the oil sorption capacity were analyzed. The results showed that polyvinyl chloride nanofibers were able to completely absorb oil without absorbing water. In addition, the results of our research showed that polyvinyl chloride nanofiber’s oil sorption capacity is inversely proportional to the temperature. Given these points, our research showed the enormous potential that polyvinyl chloride nanofibers have for removal of oil spill in water, due to their effectiveness and quickly sorption effect.